The need for redundancy is one of several reasons put forth by the City of Abbotsford when discussing why the Stave Lake water project needs to move forward.
On Monday, council heard a presentation on why redundancy has become an issue.
“As demands on our water system grow, year by year, redundancy becomes more of a concern,” said Jim Gordon, the city’s general manager of engineering and regional utilities.
Currently, the city’s water supply comes from Norrish Creek, the primary source, as well as Cannell Lake and 19 wells. In the past, if something were to happen to the Norrish Creek line, the city could still provide water from the other sources.
But city growth has increased the daily use of water.
If Norrish Creek were to be compromised, as it was in 2003 when heavy rains caused the system to be temporarily shut down, a water shortage may result.
“Our usage this month is about 70 MLD (million litres a day). We could get about 50 MLD from our wells,” explained Gordon.
The Cannell Lake permit only allows nine MLD but Gordon said it could be increased for a short period to 20 MLD to “barely meet demands.”
However, if the problem occurred in other months, like May to August, when the average use rises to more than 80 MLD, taps could run dry, he said.
“We would drain our reserves and lose fire protection. Residents in higher areas of town would have no water,” said Gordon.
Those who did still have water, said Gordon, would have little pressure and likely face a boil order.
“Every year, as our usage grows, our redundancy shrinks.”
The city wants to create a new water source and treatment centre at Stave Lake. The proposed project will cost an estimated $291 million and could be funded with up to $61 million in federal funds if it becomes a P3 (public-private partnership).
A referendum has been scheduled for Nov. 19 to allow voters to approve or reject the proposal.